Adherence to denosumab for the treatment of osteoporosis in Japanese patients with rheumatoid arthritis: Results from the IORRA cohort study

Osteoporosis is one of the major complications in patients with rheumatoid arthritis (RA) [1,2], and various osteoporosis medications are used for treatment. Among these medications, denosumab is commonly used. This agent is administered subcutaneously once every 6 months, so adherence is expected to be higher than that of other agents. Denosumab also suppresses bone erosion in patients with RA [3]. Since administration of denosumab to patients with RA and osteoporosis is expected to treat both conditions, it is considered to be highly useful in this setting. Several reports with a large amount of data from osteoporosis patients of other ethnicities about adherence to denosumab have been published [4,5], as has a report about patients of other ethnicities with RA and osteoporosis [6]. However, although a few reports that investigated adherence to denosumab retrospectively exist in Japan [7,8], no prospective studies using cohort data have been reported. The current study aimed to analyze adherence to denosumab compared with other osteoporosis medications and factors associated with discontinuation of denosumab in Japanese patients with RA using the Institute of Rheumatology Rheumatoid Arthritis (IORRA) cohort.